Floor covering for athletic facility

ABSTRACT

A multilayer floor covering is provided which is suitable for use as a playing surface of an athletic facility. The floor covering comprises a composite needlepunched material in which a fiber batt bottom layer is needled into a support layer so that a portion of the fiber batt protrudes through the top of the support layer, a layer of polyurethane elastomer adhered to the composite needlepunched material and a top wear coating of polyurethane adhered to the layer of urethane elastomer.

The present invention relates to a novel laminated material suitable foruse as a floor covering for an athletic facility.

The playing surface of an athletic facility such as a field house mustmeet many strict requirements. To meet the requirements of a particularsport such as basketball, surfaces have been used which not onlynecessitate expensive maintenance but are unsuitable for other sportsand other uses. For instance, the wooden floors used on basketballcourts must be frequently refinished and are damaged by contact withfootwear other than sneakers.

In accordance with the present invention, there is provided a floorcovering for an athletic facility which is characterized by a ruggedsurface structure, good dimensional stability, low compression set, abasketball bounce similar to that of a wooden floor, frictioncharacteristics designed for safe running and stopping, self-healingwhen penetrated by spiked shoes, ability to support loads, low slip whenwet and comfortable feel underfoot. These characteristics make thepresent floor covering material suitable as a surface for a wide varietyof sports as well as other uses such as dancing, an auditorium floor,etc.

The floor covering material is a laminate containing a number of layerseach of which performs a specific function and the combination of whichgive the properties described above. The lower portion of the laminateis a composite needlepunched material in which the bottom layer is afibrous batt that has been needled into a fabric or film support layerso that a minor portion of the batt protrudes through the support layerwhile the bulk of the fibrous batt remains as a fiber layer at least1/16 inch thick. A layer of polyurethane elastomer is adhered to thecomposite needlepunched material and a wear coating of abrasionresistant polyurethane is adhered to the top of the urethane elastomerlayer. Preferably, the elastomer is applied to the support side of thecomposite needlepunched material so that the fiber layer of at least1/16 inch thickness forms the bottom layer of the floor coveringmaterial. However, a satisfactory product can also be obtained when thecomposite needlepunched material is reversed and the elastomer adheredto the fiber layer.

Referring to the drawing, there is shown a multilayer product 10 havingas its bottom structure a needlepunched material formed from a fibrousbatt 11 which has been needled into a support layer 12 of woven fabricso that a portion of the fiber batt 11 protrudes through the top of thesupport layer, but a major portion of the fiber batt forms a layer offibers 16 on the bottom of the product. A layer of polyurethaneelastomer 14 is adhered to the top of the support layer and is coveredwith an abrasion resistant polyurethane coating 15.

The fiber batt used in the bottom layer should be at least 9 ounces persquare yard, preferably 10-80 ounces per square yard, and in the finalproduct the layer of fibers below the support layer 12 must be at least1/16 inch thick, preferably within the range of 1/16 to 5/16 inch inthickness. This layer serves as a resilient pad and provides comfortunderfoot. Additionally, this layer prevents spikes, cleats or othersimilar sharp articles from penetrating through to the floor. The fiberbatt can be made from any of the fibers commonly used in the productionof needlepunched carpeting such as nylon, polypropylene, polyester,acrylic fibers and mixtures thereof.

The fiber batt is needled into a support so that a portion of the fiberbatt protrudes through the support layer. Generally, the needle densityis in the range of about 200 to 1600 punches per square inch. Thesupport layer is preferably a woven or knitted fabric but can also be anonwoven fabric or a polymeric film. In addition to anchoring the fiberbatt, the support layer provides dimensional stability to the finalproduct. The support layer preferably has a weight of about 2 to 5ounces per square yard. Thus, the total weight of the composite of thefiber batt plus the support layer is preferably between about 12 and 85ounces per square yard. The resilience of this composite should be inthe range of about 10 to 30, measured as the percent rebound of a 7/8inch diameter, 46 gram steel ball dropped from a height of one meter.

In the preferred embodiment shown in the drawing, the portion of thefiber batt protruding through the support layer provides points of solidattachment for the subsequent layer applied on top of the support layer.Optionally, the portion of the fiber batt protruding through the supportlayer can be impregnated with a latex composition which will more firmlylock the fibers in place. It is also possible to obtain a satisfactoryproduct by reversing the needlepunched material so that the polyurethaneelastomer is applied to fiber layer 16.

When the elastomeric polyurethane layer used as less than 3/16 inch inthickness, it is sometimes difficult to obtain a product having a smoothupper surface if the side of the needlepunched material to which theelastomer layer is applied has a rough fibrous surface. To insure asmooth product when using such an elastomeric layer, it is preferable toapply the elastomer to a surface which has been impregnated with a latexcomposition as described above or to smooth the surface of theneedlepunched material such as by singeing, buffing or shearing.

The elastomeric polyurethane layer bonded to the composite needlepunchedmaterial provides resilience, ball bounce, foot comfort andself-sealing. The layer of polyurethane elastomer is preferably 3/64 to3/8 inch in thickness and weighs about 40 to 360 ounces per square yard.Other required properties of this layer are set forth in TABLE I.

                  TABLE I                                                         ______________________________________                                        POLYURETHANE ELASTOMER PROPERTIES                                             Property                Requirements                                          ______________________________________                                        Density (gm/cm.sup.3)   0.5 to 1.6                                            Hardness (Shore A).sup.1                                                                              30 to 90                                              Resilience.sup.2        20 to 50                                              Compression Set.sup.3 (percent)                                                                       maximum of 35                                         Compression Strength (10 percent                                               deflection p.s.i.)     30 to 200                                             Compression Strength (50 percent                                               deflection p.s.i.)     200 to 1800                                           Ultimate Elongation (percent)                                                                         80 -- minimum                                         Ultimate Tensile Strength (p.s.i.)                                                                    200 -- minimum                                        Tear Strength.sup.4 (p.l.i.)                                                                          50 -- minimum                                         Cold Crack (180° Bend, No Crack)                                                               Pass 40°F.                                     Water Absorption.sup.5  Maximum of 6                                          Taber Abrasion (weight loss milli-                                             grams).sup.6           Maximum of 4000                                       Flammability, Pill Test (DOC-FF-2-70)                                                                 Pass                                                  ______________________________________                                         .sup.1 ASTM D-2240-68, measured one week after curing.                        .sup.2 Percent rebound of 7/8 inch diameter steel ball weighing 46 grams      dropped from a height of one meter.                                           .sup.3 ASTM D-395, Method B, 50 percent compression for 72 hours at           23°C.                                                                  .sup.4 ASTM D-624, Die C.                                                     .sup.5 168 hours at 23°C. percent weight gain.                         .sup.6 CS 17 wheel, 500 grams per wheel, 5,000 cycles.                   

The elastomer layer is further characterized in that the holes formed by3/8 inch length needle-track spikes reclose after removal of the spikes.It is preferred that polyurethane elastomer be resistant to burningcigarettes. Such resistance is obtained by using polyurethane elastomerswhich are thermosetting, such as those obtained by reacting polyesterpolyols with isocyanates employing greater than stoichiometric amountsof isocyanate and/or using at least one reactant with a functionalitygreater than two. With therosetting polyurethanes, no surfacedeformation is caused by a cigarette laid on the surface burning fromend to end.

There are presently many known polyurethane elastomers which meet theabove requirements. Suitable polyurethane elastomers are disclosed inU.S. Pat. Nos. 3,594,352 and 3,595,814.

Specific examples of polyurethane compositions which meet therequirements of this invention are as follows:

A. the composition of Example III, U.S. Pat. No. 3,595,814. whichcontains a carbamate.

B. the compositions of Examples II and III of U.S. Pat. No. 3,594,352.

C. a composition prepared by combining 6.8 grams of a blend of crudepolyaryl polyisocyanate and diphenylmethanediisocyanate (functionality2.3, equivalent weight 133 per N=C=O group, sold commercially as PAPI901 by Upjohn Co.) with the following blend and then curing:

    Polypropylene Glycol (molecular weight 2200)                                                             53.3 grams                                         Calcined Kaolin            40.0 grams                                         Stannous Octoate           0.3 grams                                      

D. a prepolymer prepared by heating together for 3 hours at 70°C., amixture 1700 grams of poly(propylene oxide) adduct of trimethylolpropane(molecular weight 1600) and 400 grams of toluene diisocyanate (80percent 2, 4/20 percent 2,6, isomer). The prepolymer is blended with apremixture of the following composition and cured for one week at roomtemperature.

    Polypropylene glycol (molecular weight 1300)                                                             1300 grams                                         Zinc oxide                 2500 grams                                         Dibutyltindilaurate        17 grams                                           2,6 di(tertiary butyl) para cresol                                                                       4 grams                                        

E. 6.6 grams of Methylene bis (Orthochlor Aniline) are melted andblended with 150 grams of polypropylene glycol (molecular weight 2000).To this blend are added 0.06 grams of Stannous Octoate, 10 grams oftitanium dioxide and 10 grams of CaCO₃ and then 19 grams of toluenediisocyanate (80 percent 2,4; 20 percent 2,6 isomer) are added. Thecomposition is then cured for 30 minutes at 150°C.

The components of suitable compositions, such as those listed above, canbe changed in accordance with known technology to vary the properties ofthe elastomeric products within the acceptable ranges listed in

TABLE I. For instance, the crosslinking density of the above-mentionedproduct of Example III of U.S. Pat. 3,595,814 can be lowered by using ahigher molecular weight polyoxypropylene triol and/or less trimethylolpropane to give a product having a higher elongation.

The top coating of polyurethane should be about 0.5 to 6 mils thick. Thecoating should have high abrasion resistance, proper frictioncharacteristics and resistance to staining and soiling. Generally, theabrasion resistance of the top coating is much higher than that of thematerial used in the polyurethane elastomer layer.

The required properties of the top coating are given in TABLE II.

                  TABLE II                                                        ______________________________________                                        POLYURETHANE TOP COAT PROPERTIES                                              Property                  Requirement                                         ______________________________________                                        Taber Abrasion.sup.1 (weight loss in milligrams)                                                        0 to 500                                            Ultimate Elongation (percent)                                                                           80 minimum                                          Cold Crack (180° Bend)                                                                           Pass 40°F.                                   Water Absorption.sup.2    0 to 8                                              ______________________________________                                         .sup.1 CS-17 wheel, 500 grams per wheel, 5,000 cycles, total weight loss      in milligrams.                                                                .sup.2 168 hours at 23°C., percent weight gain.                   

The top coating should have the same hole resealing property as theelastomeric layer. Additionally, it is preferred that the polyurethanecomposition of the top coating be thermosetting in order to obtain aresistance to burning cigarettes similar to that of the preferredurethane elastomers.

To have a safe surface for athletic events the coefficient of frictionbetween the surface and the soles of athletic footwear cannot be too lowor it will be slippery or too high, or it will cause unduly suddenstops. In general, the coefficient of static friction between the topcoating and leather, polyvinyl chloride and neoprene, both dry and wet,should be in the range of 0.4 to 1.5 as measured by ASTM D-1894-63.

Specific examples of polyurethane top coating compositions meeting therequirements of this invention are set forth below. In each of theseexamples, the isocyanate-polylol adduct was prepared by adding theisocyanate slowly to a mixture containing the remaining ingredientswhile controlling the conditions so that the temperature did not exceedabout 60°C. The mixture was then slowly heated to about 75° to 100°C.and maintained at that temperature until the free isocyanate content wasapproximately constant.

    ______________________________________                                                                         Grams                                        (F)    Polypropylene Adipate     560                                                 (Equivalent weight 560)                                                       2,4 Toluene Diisocyanate  140                                                 Di tert. Butyl p Cresol    1                                                  Dimethyl Silicone Oil (200 CSTK)                                                                        0.2                                                 Titanium Dioxide Pigment  140                                                 Carbon Black Pigment       10                                                 Silica (passes 400 mesh)  100                                                 Silica Aerogel             30                                                 Xylol                     150                                                 Toluol                    250                                                 Ethyl Acetate             100                                          ______________________________________                                    

The mixture was formed into a thin layer and cured for one week at 35percent relative humidity to give a product having the followingproperties (measured by test methods of TABLES I and II).

    ______________________________________                                        Properties        Requirements                                                ______________________________________                                             Hardness (Shore A)                                                                             80                                                           Ultimate Elongation                                                           (percent)        180                                                          Ultimate Tensile                                                              Strength (p.s.i.)                                                                              3,000                                                        Taber Abrasion   Less than 75 milligrams loss                                 Tear Strength                                                                 (Die C, p.l.i.)  300                                                          Water Absorption                                                              (percent)        less than 2                                                  Cold Crack (180° Bend)                                                                  Pass 40°F.                                       (G)  Polyethylene Adipate                                                          (MW 2000)        63.6                                                         3,3' Diphenylmethane                                                          Diisocyanate     36.4                                                         Butylated Hydroxy -                                                                            toluene 0.1                                                  2,2',4,4', Tetrahydroxy                                                       benzophenone     0.1                                                          Silica Aerogel   5                                                            Toluol           60                                                           Methyl ethyl ketone                                                                            40                                                      ______________________________________                                    

After being formed into a thin layer and cured as in Example (F), aproduct was obtained having the following properties:

    Hardness (Shore A)                                                                              75                                                          Ultimate Tensile Strength                                                                       4,000                                                       (p.s.i.)                                                                      Ultimate Elongation (percent)                                                                   300                                                         Tear, Die C (p.l.i.)                                                                            350                                                         Taber Abrasion    Less than 50 milligrams loss                                Water Absorption (percent)                                                                      less than 2                                             

The floor covering has a total thickness of about 7/64 to 3/4 of aninch, weights about 60 to 450 ounces/square yard, has a resilience ofabout 20 to 50 as measured by the method described in TABLE I, passesflammability, pill test (DOC-FF-1-70) tested on its face, possesses aface hardness of 30 to 90 as determined by the procedure described inTABLE I and has a thermal expansion of less than 0.005 in./ft./°F. Thebasketball bounce of the product meets the minimum requirement of 49inches as determined by the NCAA test method (a regulation basketballwhich meets the required 49 inch minimum rebound specification whendropped on a hardwood floor is dropped from a height of 6 feet, measuredfrom the bottom of the ball, and the rebound height to the top of theball is measured).

Where it is desired to provide surface having a high coefficient ofstatic friction suitable for track events, this can be obtained bymodifying or roughening the product of the present invention. Thus, forinstance, a strip going around the outside of an installation can bemodified to provide a running track. Suitable procedures foraccomplishing such modification include embossing the top surface of thefloor covering and incorporating particulate matter into the top surfacesuch as by gluing particles of polyurethane elastomer to the top of theelastomer layer prior to the addition of the top coating. In themodified or roughened areas the layer of polyurethane elastomer can bethinner and can have a thickness of only 1/32 of an inch.

The floor covering is installed by adhesively bonding the bottom fiberlayer to the floor of the athletic facility. If desired, adhesives canbe used which form a moisture barrier between the floor and the bottomfiber layer.

The following example is given to further illustrate the invention, butit is to be understood that the invention is not to be limited in anyway by the details described therein.

EXAMPLE

A sample of a composite needlepunched material was prepared by needlinga batt of polypropylene fibers having a weight of 30 ounces per squareyard into a scrim of polypropylene yarn having a weight of 3.4ounces/square yard using a needling density of 800 punches per squareinch. A fibrous layer 1/5 inch thick was attached to one side of thescrim while fiber ends protruded through the other side of the scrim.The protruding fibers were impregnated with a latex coating of 7 ouncesper square yard. The resilience (measured as in TABLE I) of thecomposite product was 18.

A 1/8 inch thick layer of polyurethane elastomer was applied to thelatex coating and cured by heating at 275°F. for 20 minutes. Thepolyurethane elastomer employed was a commercially available productsimilar to the carbamate containing composition described in Example IIIof U.S. Pat. No. 3,598,814 except that it had a somewhat lower crosslinkdensity. The cured elastomer had the properties set forth in TABLE III,the test procedures being the same as those set forth in TABLE I.

                  TABLE III                                                       ______________________________________                                        Weight                 125 oz./sq. yd.                                        Density                1.4 grams/cm.sup.3                                     Hardness (Shore A)     60                                                     Resilience (Percent Rebound)                                                                         35                                                     Compression Set (Percent)                                                                            4                                                      Compression Strength 10 percent                                               deflection (p.s.i.)    100                                                    Compression Strength 50 percent                                               deflection (p.s.i.)    500                                                    Ultimate Elongation (percent)                                                                        300                                                    Tear Strength (p.l.i.) 100                                                    Cold Crack (180° Bend, No Crack)                                                              Pass 0°F.                                       Water Absorption (percent)                                                                           Less than 2                                            Taber Abrasion (weight loss in                                                milligrams)            1,000                                                  Flammability, Pill Test                                                                              Pass                                                   ______________________________________                                    

A polyurethane top coating solution was spread on top of the elastomerlayer to give a coating of about 3 mils thick. The coating compositionwas that described above in Example (F) and it was cured for one week atroom temperature and at least 35 percent relative humidity.

When the final multilayer product was walked on with 1/4 inch and 3/8inch runners needle spikes the holes in the top coating and elastomerlayers completely reclosed after removal of the spikes and when a kingsized cigarette was laid flat on the product surface and allowed to burnfrom end to end there was no deformation of the product surface. Otherproperties are set forth in TABLE IV with the test procedures being thesame as those described in TABLES I and II.

                  TABLE IV                                                        ______________________________________                                        PRODUCT OF EXAMPLE                                                            ______________________________________                                        Thickness (inches)      3/8                                                   Face Hardness (Shore A) 60                                                    Resilience (percent rebound)                                                                          35                                                    Basketball Bounce (inches)                                                                            49                                                    Taber Abrasion (mgm weight loss)                                                                      Less than 75                                          Thermal Expansion (in./ft./°F.)                                                                Less than .001                                        Cold Crack (180° Bend)                                                                         No Crack 40°F.                                 Fadeometer (hours to appearance change)                                                               200+                                                  Flammability, Pill Test, Face                                                                         Pass                                                  Coefficient of Static Friction of Top Surface                                 (ASTM D-1894-63)                                                                        Vs leather   (Wet       0.8                                                                (Dry       0.4                                                   Vs PVC       (Wet       1.0                                                                (Dry       0.6                                                   Vs Neoprene  (Wet       0.8                                                                (Dry       0.6                                         ______________________________________                                    

It will be apparent that many modifications and variations may beeffected without departing from the scope of the novel concepts of thepresent invention and the illustrative details disclosed are not to beconstrued as imposing undue limitations on the invention.

In the claims, the properties recited are based on the test methodsdescribed in the specification.

We claim:
 1. A multilayer product suitable for use as a floor coveringof an athletic facility comprising a composite needlepunched materialhaving a fiber batt bottom layer at 10 to 80 ounces per square yardneedled into a support layer of fabric or film so that a minor portionof the fiber batt protrudes through the top of said support layer and amajor portion of the fiber batt remains as a fibrous layer at least 1/16inch thick attached to the bottom of said support layer; a layer ofpolyurethane elastomer of from 3/64 inch to 3/8 inch thick adhered tothe top of said composite needlepunched material, said polyurethaneelastomer having a Shore A hardness of 30 to 90, a resilience of 20 to50 percent rebound, a compression set of not greater than 35 percent, anultimate elongation of at least 80 percent, an ultimate tensile strengthof at least 200 p.s.i., a density of 0.5 to 1.6 gm./cm..sup. 3 and atear strength of at least 50 p.l.i,; and a wear coating of polyurethanehaving a high abrasion resistance adhered to the top of said layer ofurethane elastomer said wear coating providing said multilayer productwith a smooth surface.
 2. A multilayer product as claimed in claim 1wherein said wear coating has a Taber Abrasion of 0 to 500 milligramsweight loss with a CS 17 wheel, 500 grams per wheel and 5,000 cycles. 3.A multilayer product as claimed in claim 1 wherein said polyurethaneelastomer and said polyurethane wear coating are thermoset materialswhich are resistant to burning cigarettes.
 4. A multilayer product asclaimed in claim 1 having a thickness of about 1/8 to 3/4 inch, a weightof about 60 to 450 oz./sq./yd., a resistance of 20 to 50 percent reboundand a thermal expansion of less than 0.005 in./ft./°F.
 5. A multilayerproduct as claimed in claim 1 wherein the portion of the fiber battprotruding through the top of the support layer is impregnated with alatex composition.
 6. A multilayer product as claimed in claim 1 whereinsaid wear coating provides a smooth surface having a coefficient ofstatic friction of about 0.4 to 1.5 versus dry and wet leather,polyvinyl chloride and neoprene as measured by ASTM-D-1894-63.